This commit simply updates ceph_client/tasks/ceph_auth.yml to ensure
that cinder_service_backup_program_enabled and
cinder_service_backup_driver are defined before trying to evaluate
them. On a normal deployment, this is not an issue but when running
os-nova-install.yml on an AIO where ceph support is enabled, this
variable evaluation fails as the AIO host is part of both cinder_backup
and nova_compute groups, but does not have access to these variable
defaults in os_cinder/defaults/main.yml since we're operating on the
os_nova role.
An alternate solution would be to add these variable defaults to
group_vars, however as the os_nova role doesn't actually need to use
them it's probably cleaner to just check if they're defined.
Change-Id: I2c35b14f42b2c452aa68a611ab68c612db1b07a4
Closes-Bug: #1493799
466de05c67